Margin Call - Margin Maintenance?

UPDATED my $$$ was off. It was higher than I stated.

See pics.

Do fills after 4PM EST count toward toward the MC? If so, then that explains it all.
If not, can someone explain to me on a 5th grade level WTF is happening. I just got another margin call and I do not understand why because I checked my margin maint before 4pm and exited the required positions to insecure I didn’t get a call. After hours aka 6:01, I needed to sell. Since I could not, the stock dropped 1300 and then 2000 by 8PM. There was nothing I could do since Alpaca doesn’t have true extended hours.

Anyways, what is the formula to prevent margin calls?

Margin Maintenance and what? Clearly the information I’m getting from the API is not what I’m supposed to go by. At the end of the day I had over $31,000 of buying power left. Then at 6:30 AM it disappeared and I was hit a margin call of about $5k which at the time I think was how much “negative” my total positions were. My margin maintenance was $26k yesterday. So I’m super confused.

Are the margin requirements different per stock? If so, how can I determine this via the API?